It is known to provide vehicles with extendable rearview mirrors which extend selectively from the vehicle body along a support arm which extends laterally from the body of the vehicle. This type of extendable mirror is shown for example in U.S. Pat. No. 5,572,376 issued to Pace. The Pace mirror further includes a rack gear drive and a flexible boot which provides a cover between the vehicle and the motor housing to protect portions of the apparatus from exposure. A problem with this prior art device, however, is that the slidable components of the sub-assembly and support arm produce wear of the parts, thus creating undesirable movement in the slide assembly which produces excessive vibration in the mirror assembly resulting in poor vision through the mirror. It is known to use plate springs such as shown in the above-captioned U.S. Patent to Pace to take up clearances between slide components of the extension arm mechanism however, because of the limited space between these parts, the practical use of this type of spring provides a spring force which is relatively weak in relation to the reaction forces created by the mass of the mirror sub-components.
Another extendable rearview mirror for a vehicle is disclosed in U.S. Pat. No. 6,116,743 issued to Hock. The mirror assembly of the Hock device includes a bracket which is slidable around a support arm and includes internal spring means for taking up the gap between the outer surface of the support arm and the inner surface of the bracket. This device is a complex assembly of many small parts including screws and other fasteners. U.S. Pat. No. 5,969,890 issued to Whitehead shows an extendable mirror which slides along longitudinal rails located on the outside of the mirror housing. Hence the rails are not protected from the adverse elements of the weather.
There is therefore a need in the art for an extendable rearview mirror support mechanism which is resistant to wear and which remains extremely stable and vibration-resistant throughout the entire stroke of its motion. It is further desired to provide a mechanism which is easily assembled to allow high volume manufacturing. For yet further economy of manufacture there is a need to provide a “no-tool assembly” of parts.